scholarly journals Label-Free Electrochemical Detection of S. mutans Exploiting Commercially Fabricated Printed Circuit Board Sensing Electrodes

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 575 ◽  
Author(s):  
Gorachand Dutta ◽  
Abdoulie A. Jallow ◽  
Debjani Paul ◽  
Despina Moschou
Keyword(s):  
Electrochemical Detection ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Charge Transfer Resistance ◽  
Circuit Board ◽  
Label Free ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance ◽  
Printed Circuit

This paper reports for the first time printed-circuit-board (PCB)-based label-free electrochemical detection of bacteria. The demonstrated immunosensor was implemented on a PCB sensing platform which was designed and fabricated in a standard PCB manufacturing facility. Bacteria were directly captured on the PCB sensing surface using a specific, pre-immobilized antibody. Electrochemical impedance spectra (EIS) were recorded and used to extract the charge transfer resistance (Rct) value for the different bacteria concentrations under investigation. As a proof-of-concept, Streptococcus mutans (S. mutans) bacteria were quantified in a phosphate buffered saline (PBS) buffer, achieving a limit of detection of 103 CFU/mL. Therefore, the proposed biosensor is an attractive candidate for the development of a simple and robust point-of-care diagnostic platform for bacteria identification, exhibiting good sensitivity, high selectivity, and excellent reproducibility.

scholarly journals An Electrochemical Immunosensor Based on a Self-Assembled Monolayer Modified Electrode for Label-Free Detection of α-Synuclein

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 617 ◽  
Author(s):  
Chuang-Ye Ge ◽  
Md. Mahbubur Rahman ◽  
Wei Zhang ◽  
Nasrin Siraj Lopa ◽  
Lei Jin ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Label Free ◽  
Serum Samples ◽  
Self Assembled Monolayer ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance ◽  
Label Free Detection ◽  
Self Assembled

This research demonstrated the development of a simple, cost-effective, and label-free immunosensor for the detection of α-synuclein (α-Syn) based on a cystamine (CYS) self-assembled monolayer (SAM) decorated fluorine-doped tin oxide (FTO) electrode. CYS-SAM was formed onto the FTO electrode by the adsorption of CYS molecules through the head sulfur groups. The free amine (–NH2) groups at the tail of the CYS-SAM enabled the immobilization of anti-α-Syn-antibody, which concurrently allowed the formation of immunocomplex by covalent bonding with α-Syn-antigen. The variation of the concentrations of the attached α-Syn at the immunosensor probe induced the alternation of the current and the charge transfer resistance (Rct) for the redox response of [Fe(CN)6]3−/4−, which displayed a linear dynamic range from 10 to 1000 ng/mL with a low detection limit (S/N = 3) of ca. 3.62 and 1.13 ng/mL in differential pulse voltammetry (DPV) and electrochemical impedance spectra (EIS) measurements, respectively. The immunosensor displayed good reproducibility, anti-interference ability, and good recoveries of α-Syn detection in diluted human serum samples. The proposed immunosensor is a promising platform to detect α-Syn for the early diagnose of Parkinson’s disease, which can be extended for the determination of other biologically important biomarkers.

scholarly journals Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine Modified Surface

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1929
Author(s):  
Alexander Rodríguez ◽  
Francisco Burgos-Flórez ◽  
José D. Posada ◽  
Eliana Cervera ◽  
Valtencir Zucolotto ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Neuronal Damage ◽  
Charge Transfer Resistance ◽  
Single Frequency ◽  
Response Analysis ◽  
Transfer Resistance ◽  
Therapeutic Decisions

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.

Nanomonitor Technology for Glycosylation Analysis

2009 ◽  
Vol 1236 ◽  
Author(s):  
Gaurav Chatterjee ◽  
Manish Bothara ◽  
Srivatsa Aithal ◽  
Vinay J Nagraj ◽  
Peter Wiktor ◽  
...  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protein Glycosylation ◽  
Circuit Board ◽  
Biological Macromolecules ◽  
Label Free ◽  
Alumina Membrane

AbstractChanges in protein glycosylation have great potential as markers for the early diagnosis of cancer and other diseases. The current analytical tools for the analysis of glycan structures need expensive instrumentation, advanced expertise, is time consuming and therefore not practical for routine screening of glycan biomarkers from human samples in a clinical setting.We are developing a novel ultrasensitive diagnostic platform called ‘NanoMonitor’ to enable rapid label-free glycosylation analysis. The technology is based on electrochemical impedance spectroscopy where capacitance changes are measured at the electrical double layer interface as a result of interaction of two molecules.The NanoMonitor platform consists of a printed circuit board with array of electrodes forming multiple sensor spots. Each sensor spot is overlaid with a nanoporous alumina membrane that forms a high density of nanowells. Lectins, proteins that bind to and recognize specific glycan structures, are conjugated to the surface of nanowells. When specific glycoproteins from a test sample bind to lectins in the nanowells, it produces a perturbation to the electrical double layer at the solid/liquid interface at the base of each nanowell. This perturbation results in a change in the impedance of the double layer which is dominated by the capacitance changes within the electrical double layer.The nanoscale confinement or crowding of biological macromolecules within the nanowells is likely to enhance signals from the interaction of glycoproteins with the lectins leading to a high sensitivity of detection with the NanoMonitor as compared to other electrochemical techniques.Using a panel of lectins, we were able to detect subtle changes in the glycosylation of fetuin protein as well as differentiate glycoproteins from normal versus cancerous cells. Our results indicate that NanoMonitor can be used as a cost-effective miniature electronic biosensor for the detection of glycan biomarkers.

scholarly journals Commercially Fabricated Printed Circuit Board Sensing Electrodes for Biomarker Electrochemical Detection: The Importance of Electrode Surface Characteristics in Sensor Performance

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 741 ◽  
Author(s):  
Gorachand Dutta ◽  
Anna Regoutz ◽  
Despina Moschou
Keyword(s):  
Electrode Surface ◽  
Linear Response ◽  
Printed Circuit Board ◽  
Limit Of Detection ◽  
Surface Characteristics ◽  
Glucose Biosensor ◽  
Circuit Board ◽  
Printed Circuit ◽  
Sensor Performance ◽  
Immobilized Glucose Oxidase

Here we report the first PCB-implemented electrochemical glucose biosensor usingcovalently immobilized glucose oxidase (GOx) on the commercially fabricated PCB electrodesurface, taking particular care on the electrode surface characteristics and their effect on sensorperformance. Based on the results, this assay exhibits a highly linear response from 500 μM to 20mM (R = 0.9961) and a lower limit of detection of 500 μM.

scholarly journals CortiWatch: watch-based cortisol tracker

2019 ◽  
Vol 5 (9) ◽  
pp. FSO416 ◽  
Author(s):  
Paul Rice ◽  
Sayali Upasham ◽  
Badrinath Jagannath ◽  
Roshan Manuel ◽  
Madhavi Pali ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Cost Effective ◽  
Circuit Board ◽  
Electrochemical Technique ◽  
Label Free ◽  
Printed Circuit ◽  
Electrochemical Testing ◽  
Testing Techniques ◽  
Small Form Factor ◽  
A Current

Sweat-based analytics have recently caught the attention of researchers and medical professionals alike because they do not require professionally trained personnel or invasive collection techniques to obtain a sample. The following presents a small form-factor biosensor for reporting physiological ranges of cortisol present in ambient sweat (8–151 ng/ml). This device obtains cortisol measurements through low volumes of unstimulated sweat from the user’s wrist. We designed a potentiostatic circuit on a printed circuit board to perform electrochemical testing techniques. The detection modality developed for quantifying sensor response to varying cortisol concentrations is a current based electrochemical technique, chronoamperometry (CA). From the results, the sensor can detect cortisol in the physiologically relevant ranges of cortisol; thus, the sensor is a noninvasive, label free, cost-effective solution for tracking cortisol levels for circadian diagnostics.

Breast cancer detection using charge sensors coupled to DNA monolayer

2015 ◽  
Vol 1793 ◽  
pp. 19-26
Author(s):  
Marina R. Batistuti ◽  
Marcelo Mulato ◽  
Paulo R. Bueno
Keyword(s):  
Breast Cancer ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Electrochemical Impedance ◽  
Redox System ◽  
Charge Transfer Resistance ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Transfer Resistance ◽  
Complementary Dna

ABSTRACTWe report the development of a label-free biosensors based on DNA hybridization, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This study uses DNA sequences based on microRNA related with breast cancer. The biosensor was fabricated by immobilizing a self-assembled monolayer of single-stranded 23-mer oligonucleotide (ssDNA) via a thiol linker on gold work electrodes. Residual binding places were filled with 6 -mercaptohexanol (MCH). The electrode was electrochemicaly characterized in the presence of a redox system ferri/ferrocyanide. Different concentrations of complementary DNA sequence for hybridization were incubated; an increase of charge transfer resistance (Rct) was observed, used as sensor parameter and correlated with concentrations of complementary DNA sequence. A debate was presented on the effect of the MgCl2 influence on ssDNA immobilization solution.

Synthesis and Electrochemical Properties of Y-Doped SnO2/C Composite Materials for Lithium-Ion Battery

2011 ◽  
Vol 197-198 ◽  
pp. 1157-1162 ◽  
Author(s):  
Sheng Kui Zhong ◽  
You Wang ◽  
Chang Jiu Liu ◽  
Yan Wei Li ◽  
Yan Hong Li
Keyword(s):  
Particle Size ◽  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Precipitation Method ◽  
Cyclic Voltammograms ◽  
Sem Images ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance

The layered Y-doped SnO2/C anode materials were prepared by a co-precipitation method. The physical properties of the Y-doped SnO2/C were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements. XRD studies showed that the Y-doped SnO2/C has the same layered structure as the undoped SnO2/C. The SEM images exhibited that the particle size of Y-doped SnO2/C is smaller than that of the undoped SnO2/C and the smallest particle size is only about 1µm. The Y-doped SnO2/C samples were investigated on the Lithium extraction/insertion performances by charge/discharge, cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). The results showed that the optimal doping content of Y was that x=0.07 and 2% content of carbon nanotubes samples to achieve high discharge capacity and good cyclic stability. The electrode reaction reversibility and electronic conductivity were enhanced, and the charge transfer resistance was decreased through Y-doping.

scholarly journals A Portable RT-LAMP/CRISPR Machine for Rapid COVID-19 Screening

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 369
Author(s):  
Meysam Rezaei ◽  
Sajad Razavi Bazaz ◽  
Dorsa Morshedi Rad ◽  
Olga Shimoni ◽  
Dayong Jin ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Limit Of Detection ◽  
Circuit Board ◽  
Proportional Integral Derivative ◽  
Early Screening ◽  
Heater Element ◽  
Printed Circuit ◽  
Preventative Measures ◽  
Fast Screening ◽  
Portable System

The COVID-19 pandemic has changed people’s lives and has brought society to a sudden standstill, with lockdowns and social distancing as the preferred preventative measures. To lift these measurements and reduce society’s burden, developing an easy-to-use, rapid, and portable system to detect SARS-CoV-2 is mandatory. To this end, we developed a portable and semi-automated device for SARS-CoV-2 detection based on reverse transcription loop-mediated isothermal amplification followed by a CRISPR/Cas12a reaction. The device contains a heater element mounted on a printed circuit board, a cooler fan, a proportional integral derivative controller to control the temperature, and designated areas for 0.2 mL Eppendorf® PCR tubes. Our system has a limit of detection of 35 copies of the virus per microliter, which is significant and has the capability of being used in crisis centers, mobile laboratories, remote locations, or airports to diagnose individuals infected with SARS-CoV-2. We believe the current methodology that we have implemented in this article is beneficial for the early screening of infectious diseases, in which fast screening with high accuracy is necessary.

scholarly journals A Mechanically-Adaptive Polymer Nanocomposite-Based Intracortical Probe and Package for Chronic Neural Recording

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 583 ◽  
Author(s):  
Allison Hess-Dunning ◽  
Dustin Tyler
Keyword(s):  
Printed Circuit Board ◽  
Primary Motor Cortex ◽  
Electrochemical Impedance ◽  
Polymer Nanocomposite ◽  
Neural Recording ◽  
Circuit Board ◽  
Probe Design ◽  
Sprague Dawley ◽  
Electrochemical Impedance Spectra ◽  
Causes Of Failure

Mechanical, materials, and biological causes of intracortical probe failure have hampered their utility in basic science and clinical applications. By anticipating causes of failure, we can design a system that will prevent the known causes of failure. The neural probe design was centered around a bio-inspired, mechanically-softening polymer nanocomposite. The polymer nanocomposite was functionalized with recording microelectrodes using a microfabrication process designed for chemical and thermal process compatibility. A custom package based upon a ribbon cable, printed circuit board, and a 3D-printed housing was designed to enable connection to external electronics. Probes were implanted into the primary motor cortex of Sprague-Dawley rats for 16 weeks, during which regular recording and electrochemical impedance spectroscopy measurement sessions took place. The implanted mechanically-softening probes had stable electrochemical impedance spectra across the 16 weeks and single units were recorded out to 16 weeks. The demonstration of chronic neural recording with the mechanically-softening probe suggests that probe architecture, custom package, and general design strategy are appropriate for long-term studies in rodents.

Sign in / Sign up

Export Citation Format

Share Document